Variable displacement pump or motor



v July 13, 1939- E.` K. BENEDl-:K 2,166,114

VARIABLE DISPLACEMENT PUMP 0R MOTOR Filed DSC. 24, i934 7 Sheets-Sheet 2@WML 46) 49 ELEKKEJENEDEK.. ,l p m/ July 18, 1939. E. K. BENEDEK2,166,114

VARIABLE DISPLACEMENT PUMP OR MOTOR Filed Dec. 24, 1934 7 Sheets-Shea?l3 July 18, 1939. E. K. BENEDEK VARIABLE DISPLACEMENT PUMP OR MOTOR 7Sheets-Sheet 4 Filed Dc. 24, 1934 v ELEKKBQIEDEK TE E f- 1' .JJ .55, I

July '18, 19.39. E. K. BENEDEK "IT-115-15- ELEKKEENEDE- A @a4 i Ta-E1-'512D Patented July 1 8, 1939 UNITED' STATES PATENT OFFICE VARIABLEDISPLACEMENT PUDIP OR MOTOR 18 Claims.

This invention relates to variable displacement pumps and motors of theradial piston or plunger type having a. primary and secondary rotor andthe principal object is to improve the eiciency andV pressure capacityof 'such mechanisms.

An object is to provide a new and improved arrangement for connectingthe pistons with the necessary reactance means for reciprocating thepistons.

Another object is to arrange the cooperative relationship between thereactance means and the pistons in a manner such that al1 moments of theresultant forces are resisted by reactionary u forces vset up in thereactance means without reactionary forces between the pistons and theirsupporting walls.

A correlative object is to arrange these elements relative to theirrespective rotors in a manner such that the reactionary forces on therespective rotors which might tend to cause moments of one rotor withrespect to the other are directed parallel to each other and through`the axes of the respective rotors whereby the forces acting on eitherrotor are balanced therein and do not create relative moments of onerotor with respect to the other.

Another object is to provide a piston crosshead thrust plate arrangementcapable of being ad- Justed so that the pump or motor operates withoutany binding whatsoever and which is adapted to be simply and denitelylocked in proper position to secure such freedom of operation.

A further object is to provide a hydrostatically balanced'variablestroke mechanism operable as a pump or motor and having a new andimproved piston operating reactance arrangement.

A further object is to provide for the reduction of bending stresses onthe necessary thrust connections between the reactance means andpistons.

Other objects and features, including thelgeneral simplicationof pump ormotor design of `the class referred to, will become apparent from thefollowing description of the invention with reference to theaccompanying drawings.

Referring briefly to the drawings:

Fig. 1 is a plan view of an entire pump or motor mechanism showing thefluid feed connections and impeller shaft;

Iig. 2 is a central longitudinal fragmentary sectional view showing themain working parts (pintle, primary rotor or barrel and secondary rotorcomprising two-face plates and support Il therefor) of one form of pumpor motor according to Fig. 1, the section being indicated by the line 22 on Fig. 1;

Fig. 3 is a transverse sectional view corresponding to Fig, 2 and asindicated by the line 3 3 on Fig. 1 and line 3a--3a on Fig. 2;

Fig. 4 is a sectional view taken substantiallyalong the line 3b 3b ofFig. 2 but with all the pistons and crossheads removed so as to show'oneface plate in elevation and the entire set of thrust plates in section;

Fig. 5 is an enlarged view showing a piston and its crossheads in themanner of Fig. 3, but with the piston inclined (exaggerated) withrespect to the crosshead proper to' show the, preferred iiexibleconnection between the pistons and crossheads;

Fig. 6 is a view of one piston and its crosshead shown in the manner ofFig, 3, but with the thrust plate at one side of the crosshead as whenthe reactance assembly is adjusted eccentrically of 20 the primaryrotor;

plates and radially opposite sides of slots in the :l0l

crossheads, the views being respectively indicated by the lines 8 8 onFig. 9 and 9 9 on Fig. 8;

Fig. 10 is a plan view of the needle bearing assembly including the cagearrangement of Figs. 8 and 9;

Figs. 11 and 12 are side and end elevations respectively of the thrustplate arrangement of Figs. 2 to 4;

Fig. 13 is a fragmentary side elevation of the -outer end of one of thepistons in the arrange- 40 ment according to Figs. 5 and 6;

Fig. 14 is a fragmentary sectional view of a modified crosshead andreactance connection means, the view corresponding to the showing at theupper portion of Fig. 2; 45

Fig. 15 is a view of said modified form of ma- L chine taken along theline |5 -I5 on Fig. 14, this view corresponding in general to Fig. 3;

Fig. 16 is a diagram showing the forces operat-j r piston and crossheadaccording to Figs. i4 and l5, the view being taken along the line I8-I8on Fig. 14;

Fig. 19 is a fragmentary sectional view taken along the line I9-I9 onFig. 14;

Figs. 20 and 21- are side and end elevations respectively of the needleroller bearings employed, for example, in the arrangement of Figs. 14and 15 to support the ends of the crosspins;

Fig. 22 is a longitudinal fragmentary sectional view taken on the line22-22 on Fig. 23 of still another modified machine, the viewcorresponding in general to Fig. 2;

Fig. 23 'is a transverse sectional view taken along the line 23--23 onFig. 22; and

Fig. 24: is a' fragmentary sectional view of a portion of one of therotary reactance plates, the section being taken at 24-24 on Fig. 22;and

Figs. 25 and 26 are diagrams showing the forces imposed by the pistonoperating connections between the primary and secondary rotors in anexemplary form of my improved mechanism acting as a pump.

In all forms of the invention shown-the piston crossheads are connectedwith the reactance means in such manner that the combined pistonoperating forces are distributed to the pistons and crossheads purelyradially of the piston carrier 0r rotor. In all forms antifrictionneedle bearings of the capillary vtype are used to eliminate all slidingfriction in the necessary generally tangential relative movement betweenthe piston and reactance means connections.V

The actual crosshead connection is shown in three types. In the first tobe described, thrust plates are provided in slots in the crossheads andantifrictional bearings are interposed between bothsides of each thrustplate and the adjacent 'walls of the slot in each crosshead. asufficient number of the bearings to carry the load being always in linewith the pistons. In the second solution of the problem the thrustplates are replaced by two or more crosspins, each antifrictionallyjournalled infixed sockets in the face plates. Here again the operatingforces on the pistons are truly radially of the piston' carrier. In thethird solution two or more crosspins are antifrictionally journalleddirectly in the crossheads and the ends of the pins ride in suitableslots which may be very easily formed in the face plates of thereactance rotor as will be shown below.

' I as by bolts 5, two of each set of bolts being shown. 'I'he mainfluid feed 'connections Aare associated with the casing part 2 having an,enlarged hub 6 carrying the pintle I0, the hub having ports at eachside receiving the mains Iand 8, the latter being interchangeably usedas pressure and discharge uid lines. Y

y Referring to Fig. 2, valve pintle I0 has a relatively enlarged portionI I, press tted. e. g., into a central axial bore of the hub 5 andisprevented from outward movement (to the left)V with respect to the hubby a shouldered flange I2 on the pintle adapted to abut the adjacent endwall ysurface of the hub. The working surface of dle rollerA assembliesI'I and.- I1' for normally mechanically preserving uniform clearance allaround the pintle working surfaces while allowing free passage of theWorking fluid past the bearings. The rotor 25 has a central bore 20receiving the pintle, the bore terminating at 20' forming a closedchamber 2I adjacent the inner end of the pintle. The central portion 20of the bore is hydraulically fitted to the pintle surface I5 andrespective portions of the bore form suitable raceways for the bearingassemblies I1 and I'I. The pintle ports are shown at I8 in the workingsection of the pintle. The impeller shaft of the rotor, indicated at 3|,extends outwardly through a suitable central opening in the end plate 3of the casing.

The mounting for the primary rotor or piston barrel 25 comprisesantifrietion bearings 26, these having inner and outer races 28 and 29respectively Iaxially abutting accurately formed surfaces on or in thecasing section 2 and 3 respectively and shouldered end portions of thebarrel. The bearings may be adjustable and are vdesigned for both radialand axial thrust. Suitable means (not shown) for taking up the axialthrust and thereby all play in the bearings, may be provided-forinstance in accordance with my prior application Serial No. 754,753, ledNovember 26, 1934.

My said prior application discloses an arrangement for truly balancingthe hydraulic forces between the working sections of the pintle I0 androtor bore 20 and this comprises a working uid feed duct 30 centrally ofthe pintle which discharges into the space 2I between the end of therotor bore and the pintle. lThe duct 30 is communicated, as shown in mysaid application, with the pressure line side of the machine s that,during the entire running operation of the machine, the working fluid isforced into and along the perimetral space between the pintle androtorbore, which space is initially maintained mechanically by the pilotbearings I1 and I 'I'.

The pistons 35, Figs. 2 and 3, operate in radial cylinder bores 35.having reduced port outlets at 36' leading to the bore 20 of the barreland adapted to register with the pintle ports I8 which lattercommunicate with respective axial feed ,and/or discharge ducts I9 (Fig.3) in the pin` tle. The pistons preferably have two or three partcrossheads so as to allow axial deflection of the crossheads proper.with respect to the working portions of the pistons. As shown, see alsoFigs. 5- and 6, the piston crossheads comprise blocks 40 relatively widein the plane of the pistons and relatively narrow transversely, theblocks being slidable in radial ways 4I in a central drivingflange 42 ofthe rotor, see particularly Fig. 2, the flange being centrally disposedwith respect to the transverse plane of the pistons" and extending totheouter ends of the crosshead elements when -the barrel is inconcentric relation The crossheads, on their inner sides, toward thepistons, have transverse channels 43 each provided with twounderlianging lips 44. The channels 43 are formed to receive thrustblocks 45 which accurately t Ithe channels on three sides,

the fourth side being arcuately surfaced as at 46 complementary to thearcuate surface 41 on the. enlarged head portions 48 of the pistons.Preferably the heads 48 and the mating surfaces of the blocks 45 arearcuate transversely as Well as in planes parallel to the general planeof the Ito the reactance assembly as shown in Fig. 3.

pistons, this being shown in Fig. 10, so that, in -75 the event ofdisalignment between the pistons and crossheads in either intersectingcentral normal plane of the piston axes, there will be no bindingbetween the pistons .and the crossheads. Preferably there is sufficientclearance (several thousandths of an inch) between the under sides ofthe piston head formations 48 and the lips Il as diagrammaticallyindicated at 49, Fig. 5, so that the maximum expected deflection undermaximum torque force T will not cause the pistons and crossheads to bindin their respective guideways inwardly from the head portions-toward theaxis of the barrel:

The reactance means operating on the crossheads comprise. as shown, faceplates 50, one at each side of the radial flange I2 and close thereto.These face plates have annulan disc-like flange formations at 5I lyingadjacent the driving flange 42 and tubular flanges 52 for engagementwith a suitable rotary support. As shown, the support comprises ballbearing assemblies, one for each face plate and the assemblies includeballs 55 and inner and outer rings 56 and 51. The outer bearing ringmembers 51 are suitably secured in a. common adjustment ring 56,-

part only of which is shown but which, as shown in my said priorapplication, is mounted to slide in general casing transversely of thepintle and cylinder barrel axes. The adjustment means may comprisesuitable bars arranged on opposite sides of the adjustment ring andprojecting into the casing through suitable aligned bores therein, oneof such bores being indicated at 59, Fig. 1.

Each of the face plates, as shown in Figs. 2 and 4, is arcuatelyvgrooved as at 60 adjacent the crossheads 4U and the crossheads aretransversely slotted as at 62 for receiving thrust plates 63, theopposite ends 65 of the thrust plates extending into the respectivegrooves 60 of the face plates. As shown, each thrust plate has a centralportion which has planar parallel surfaces on the opposite sidesradially of the'machine. These planar surfaces extend only to thelateral limits of the crossheads and beyond these limits, in bothdirections axially of the machine, the thrust plates are arcuatelyformed as at 65a and 65h to fit the slots 60 for circumferentialadjustment therein. The detailed construction is best illustrated inFigs, l1 and 12. 'Ihus the thrust plates are fully supported over wideareas in the grooves Y 60 of the face plates and are neverthelessadjustable circumferentiallyl for initial setting in proper position.

' If the thrust plates are to be secured rigidly in the face plates ascontemplated in this embodiment it is necessary that the slots 62 in thecrossheads be wide enough to permit tangential movement of the thrustplates in both directions from a central position, the distance beingdetermined by the maximum eccentric adjustment of the main adjustmentring carrying the thrust plates. It is, moreover, necessary to providesome means vfor guidingthe crossheads on .the thrust plates. Heretoforein arrangements of this type, the thrust plates were merely made to fitthe slots and slide directly thereon with great frictional` waste. Iprovide instead a series of antifriction needle bearings of thecapillary type between both the inner and outer surfaces of the thrustplates and the outer and inner slot surfaces of the crossheads. Theseneedle bearings are indicated at 61 and 68 and are mounted in thebearing space so that they may freely rotate with respect to each otherin rolling contact with the Iuntil the barrel turns entirely freely.

thrust plate and crosshead surfaces. With this in view I provide ageneral cage for each series of needle bearings as shown in Fig. 13, seealso Figs. 8 and 9. Fig. 13 shows side rail members 1l! connected by endrail members 1| forming a complete cage. The disposition of the rollersin the reactangular cage is such that the rollers are, at no time, tightin the cage, that is, pressed against each other. This may beaccomplished by rst illling the cage and then removing one or tworollers. l

Preferably the side rail members 10 overhang and underhang the ends ofthe'needle bearings and this will, of course, necessitate clearancespaces for the overhanging and underhanging parts of the cage. For thesake of clearness of illustration no cages or clearance spaces are shownin Figs. 2 and 3.

For greater rigidity and accuracy of operation the face plates 50,particularly the disc-like flange formations 5l thereof, are secured toeach other through the medium of suitable transverse bolts 13 which mayhave suitable spacing sleeves 14, see Fig. 7, the spacing sleevespreventing sliding contact between the inner faces of the face platesand the adjacent faces of the driving flange and the crossheads. 'I'hesecuring bolts pass through enlarged openings 15 in the radial drivingflange, the openings being large enough to admit free circular movementof the securing bolts and spaces therein incident to the relativeeccentricity of the face plates and cylinder barrel.

It will be noted that the thrust plates, notwithstanding the arcuateends, are insertable through the crosshead slots, the bearings being putin afterward.

- When the rossheads, pistons, thrust plates and bearings are assembledand the face plates brought into position with-respeetto+the ends of thethrust plates, the thrust plates may then be nicely adjustedcircumferentially of the machine the ends of the thrust plates may be'locked as by appropriate set screws 16, see particularly Figs. 2 and 4,the set screws engaging the arcuate end portions of the thrust plates atany suitable position, preferably centrally thereof as indicated in Fig.4. Additional separate locking screws (not shown) may be provided toheld the set screw in place,

It will be seen that when the thrustplates are fastened firmly in thismanner the forces acting on the piston are such that the piston issubjected only to a direct axial thrust and the rotors themselves do nottend-to build up moments with respect to each other which,A did suchexist, would have to be withstood bythe pistons and crossheads whichconstitute the only driving connection between the rotors.

Referring rst to Fig. 25, these'forces and reactions, insofar as theyaffect the rotors them- Thereafter ,-g

selves are diagrammaticallyv illustrated. The" force Fes is directedradially of the secondary rotor, that is, directly through the.eccentric C2. This force is balanced by an equal and oppositereactionary force F'sa through the eccentric axis Cz and along thecenterline of the thrust -piate Yor reactance means 63. Thus the forceF63 produces no moment of the. eccentric rotor but the entire thrust istaken directly in the bearings 55 (see Fig. 2) which are concentric withthe secondary rotor about the axis Cz. The reactionary force Rss of the-pist'on is necessarily along the axis of the piston which passesthrough the center Ci of the primary rotox and is resisted by the vtheir respective rotational axes and are passed directly to the bearingsand 26 (Fig. 2) respectively. These forces, insofar as they tend tocreate moments of one rotor with respect to the other.

are thus rendered ineffective and disposed of once and for all.

Referring next to Fig. 26, the effect of the forces, insofar as theyconcern the pistons, the I thrust plates 63, and crossheads, areillustrated. In this instance, the force Fes is balanced by areactionary force R63, both of which, due to the f-act that any rockingor twisting of the plate 63 is resisted in the eccentric rotor itself,are parallel to the center line P of the piston. Both forces, however,are offset from each other an amount equal to the instantaneouseccentricity e. Therefore, were the plate 63 free to rock about atransverse axis, such as indicated at Y, the piston 36 or crosshead I0would have to resist a moment equal to F63 times e, e being theinstantaneous eccentrieity, which moment would tend to cause reactionaryforces X between the pistons and crosshead and their respective guidingguide walls with resultant wear on all of these' members and the walls.In other words, if the plate 63 were free so to rock, the reactionaryforces C and D, which in the present structure are provided in thesecondary rotor, would be transferred and applied as the reactions X. Itwill be seen, therefore, that xing the plate 63 so that it cannot rockprovides the reactances C and D between the secondary rotor and plate 63so that the reactarices X are unnecessary. for completing equilibrium ofthe forces. The pistons and crossheads, therefore, are entirely freefrom reactionary forces, such as indicated at X, tending to cause wearof. either or locking.

In this particular embodiment of the invention, therefore, the forcesacting on either rotor are balanced therein and do not create relativemoments of one rotor with respect to the other, and the forces appliedto the pistons are so directed that they do not impose any side thrustson the pistons and crossheads.. The sameI results are accomplished inthe other embodiments herein illustrated, as will be readily apparentfrom the foregoing detailed analysis.

In the second solution of the problem, see Figs. 14 to 20 inclusive, thethrust plates are replaced by individual cross-pins 80, a plurality ofwhich are provided for each crosshead. These are balanced in the slots82 in the crossheads on opposite sides of the piston axes and in thecase of using three crosspins, one is centrally disposed with respect tothe piston'and the other two are disposed equal distances from thecentral pin but spaced from the ends of the slots for the requiredrelative travel of the crossheads and pins. The intermediate portions ofthe crosspins roll freely in the slots 82 and the ends of the pins arexedly secured in the face plates in needle bearing assemblies 84, sothat, though the pins 80 may rotate freely about their respective axes,the resultant assemblages of pins, taken as a single thrust means,cannot rotate bodily. As shown, these needle bearing assemblies haveseparate bushings 85 in appropriate bores in the face plates 50 and, ifdesired, the needles may be closed in by suitable annular plates (notshown) ing the bearings of lubricant. Here again the races are notentirely filled with the needles (packed in) but adequate space isprovided so that the needles always roll freely. It will be l noted thatthe pins are 'relatively short and that the face plates are made to ridealmost directly on the crosshead surfaces, only a few thousandthsclearance being provided between the inner face plate surfaces and theaxially facing crosshead surfaces. Thereby bending strains on thecrosspins 80 are minimized. As indicated in Fig. 16, the outwardpressure forces of the pistons, shown by arrows at A, oppose the inwardforces of the reactance means, indicated at B; the two sets of forcessubjecting the pins to shearing stresses .only at the almost negligibleunsupported portions.

With reference to Fig. 18, it will be seen that on relative tangentialmovement between the cross pins and face plates the pins simultaneouslyroll on either the inner or outer faces of the slots 82 depending onwhether the pistons ar'e effecting their pressure or suction strokes(see arrows 802) indicating the rotation. o'f the pins-say on the innerslot surfaces when the crosshead moves according to the arrow 80aoneasier to locate the bores for the bushings 85 as on an indexingmachine head, where such arcuate arrangement of crosspins is used.

Referring now to the third solution, Figs. 22 to 24, this comprises thesame general arrangement of crosspins 80 but the needle bearings 84' aresupported directly in the crossheads 40 instead of in the face plates.Again annular plates (not shown) may be provided to close the boresadjacent the needle ends and the needles are provided with sufficienttotal clearance that free rolling of the needles is assured. The deviceis somewhat simpler than that previously described partly in that itreduces the number of needle bearing assemblies necessary for a completeinstallation and, moreover, it simplifies machining of the face plates50. It is easier to form the slots 85 in the face pl-ates for receivingthe ends of the crosspins 88" as on an indexing fixture for an endmilling machine, rather th-an having to breach the crossheads to formsuch slots. It is also contemplated that instead of chordal slots 85,such as shown inr Fig. 24, single circumferential slots comparable tothe slot in Fig. 4 may be used to support -the ends of the crosspins80'. If the slot is continuous the reactance assembly E50- 55, ctc., hasto be started in rotation whenever the machine begins operating. Suchinitiation of rotation may be accomplished by the spacers 14 on the.securing bolts 13, these engaging the enlarged openings 15 of thedriving flange to start the reactance assembly rotating in any eccentric`adjustment of the said assembly relative to the cylinder barrel.

I claim:

1. In a Variable displacement pump or motor of the radial piston type, aeasing, primary and secondary rotors in the casing, one carrying a setof pistons and crossheads and radial guides for the crossheads and theother paired reactance means for the crossheads and having radial walls,the crossheads being disposed between barrel in the zone of thecylinder, a radial guide- Y the radial walls of the reactance means inslid'- on lall 4sides to maintain the4 rollers grouped in' ing relationthereto, slots in the radial walls of the reactance means extending pastthe crossheads in both directions circumferentially thereof, thrustplates having tangential portions guided in the crossheads respectivelyfor oscillation therein tangentially of. the machine, said thrust plateshaving end portions received in said slots of the reactance means,`andmeans for securing the plates in said slots in fixed circumferential-position Arelative to the reactance means, said slots and last namedmeans constraining the ranged generally tangentiallyof the machine, and

having planar surfaces generally normal to the piston axis, thrustplates extending through said slots and having their ends anchored inrespective face plates and constrained thereby from .bodily rotationrelative thereto, said thrust plates having planar surfaces opposite theplanar `surfaces of the crosshead slots, a series of free capillaryneedle rollers disposed between said planar surfaces of the thrustplates and of the slots, and means loosely embracing the rollersposition in line with the pistons.

ment radial piston type, a primary rotor and valve plntle therefor,cylinders and pistons carried by said rotor, crossheads for the pistons,a secondary rotor comprising face plates embrac-i ing the crossheads onopposite sides thereof, means to support said rotors for relativelyeccentric adjustment, slots in said crossheads having radially oppositeplanar tangential surfaces, thrust plates having .opposite planartangential surfaces disposed in said slots, said plates having theiropposite ends` anchored in said face plates and constrained frommovement relative to the face plates, and capillary needle rollersinterposed between the planar surfaces of the crosshead slots and thrustplates in alignment with the pistons.

4. In a pump or motor of the radial piston variable displacement type, aprimary rotor, pistons carried by the primary rotor, a valve plntlecooperatively arranged with respect to the rotor, a secondary rotorcomprising face plates on opposite sides of the pistons and means toadjust the same e'ccentrically of the primary rotor, crossheads for thepistons and radial guides for the crossheads in the primary rotor,parallel grooves in the face plates on opposite sides of the crossheads,slots in the crossheads generally parallelI 5. .In a rotary, radialpiston pump or motor, a

rotatable barrel having a radial cylinder, valve means for thecylinders, a radial flange on the Way in the flange having guidesurfaces parallel to the cylinder axis and positioned in advance of andto the rear of the cylinder respectively, a piston reciprocable in thecylinder, a rotary reactance eccentric to the barrel and having Wallsdisposed closely alongside the end faces of the flange, a headfon thepiston reciprocable radially Within and guided by the radial guidewayand having a way extending tangentially fore and aft from the pistonaxis, means connected to the reactance and accommodated in saidtangential way for oscillation therealong; said means dening atangentiallyelongated thrust surface fixed against all movementsrelative to the reactance rotor and engaging the tangential Way bothfore and aft of the piston axis at all times.

6. In a rotary, radial piston pump or motor, a rotatable barrel having aradial cylinder, valve means for the cylinder, a radial guideway in theflan'ge having guide surfaces parallel to the Cylinder axis, a pistonreciprocable in the cylinder, a radial head member on theA pistonreciprocable radially in the flange guideway and guided thereby, arotary reactance member eccentric to the barrel and extending alongsidethe flange and radial head member, thrust means carried byA thereactance member and extending transversely of the head memberA anddefining parallel inner and outer reactance surfaces extending forwardlyand rearwardly from the piston axis, said head member havingcomplementary Ways parallel to and operatively associated with saidinner and'outer reactance surfaces respectively for reciprocatingthepiston and for transmitting torque through the medium lof the radialhead member between the barrel flange and reactance member, and`accommodating the said thrust means for oscillation therealong forwardlyand rearwardly along the path of rotation, and means securing the thrustmeans to said reactance memberl with said reactance surfaces in fixedposition tangentially thereof and constrained against bodily rotationrelative to both members.

7. In a rotary, radial piston pump or motor, a rotatable barrel having aradial cylinder, valve means for the cylinder, a radial flange on thebarrel in the zone of the cylinder, a radial guide- Way in the flangehaving guide surfaces parallel to the cylinder axis and positioned inadvance of and to the rear of the cylinder respectively, a pistonreciprocable in the cylinder, a rotary reactance member eccentric to thebarrel and having walls disposed closely alongside the end faces oftheange respectively, a radial head member von the piston reciprocableradially in and guided by the radial guideway, one of said membershaving tangential inner and outer parallel ways extending fore and aftbeyond the piston axis, a plurality of thrust pins mounted in one ofsaid members for individual rotation about their own axes respectivelyand with their axes fixed in position with respect to the member inwhich they are mounted and positioned todene' an inner and an outertangential surface extending fore and aft beyond the piston axis, andsaid pins being accommodated between the ways of the other member forrolling oscillation therealong.

8. In a rotary, radial piston pump or motor, a rotatablebarrel having aradial cylinder, valve means for the cylinder, a radial ange on thebarrel in the zone of the cylinder, a radial guideway in the flangehaving guide surfaces parallel to the cylinder axis, and positioned inadvance of `and to the rear of the cylinder respectively, a

piston reciprocable in the cylinder, a radial head on the pistonreciprocable radially between and guided by the flange guide surfaces,andhaving a tangentially extending operating way, a rigid thrust plateaccommodated in the tangential operating way and connected at its endsto the reactance in fixed position and non-rotative relation withrespect to the reactance and having a tangential portion in thetangential operating way in cooperation therewith both fore-and aft ofthe piston axis concurrently at all times.

9. In a rotary, radial piston pump or motor, a rotatable barrel having aradial cylinder, valve means for the cylinder, a radial flange on thebarrel in the zone of the cylinder, a radial guideway in the flangehaving guide surfaces parallel to the cylinder axis and positioned inadvance of and to the rear of the cylinder respectively, a pistonreciprocable in the cylinder, a rotary reactance eccentric to the barreland having Walls disposed closely alongside the end faces of the flangerespectively, a radial head on vthe piston reciprocable radially in andguided by the radial guideway,and having a tangential way extending foreand aft from the piston axis,a plurality of thrust pins mounted at theirends in the reactance for rotation about their individual axes, and withtheir axes in a common tangential plane, and defining a tangentialthrust means' which is non-rotative bodily with respect to thereactance, said pins being accommodated in said tangential way of thehead for oscillation therealong.

10. In a rotary, radial piston pump or motor, a rotatable barrel havinga radial cylinder, valve means for the cylinder, a radial flange on thebarrel in the zone of the cylinder, a radial guideway in the flangehaving guide surfaces parallel to the cylinder axis and positioned inadvance of and to the rear of the cylinder respectively, a pistonreciprocable in the cylinder, a rotary reactance eccentric to the barreland having walls radial head on the piston reciprocable radiallyv inand' guided by the radial guideway, a plurality of thrust pins in thehead, each pin extending laterally beyond the flange and beingaccommodated at its ends in said-tangential ways for oscillationtherealong, said pins being positioned to engage said Ways concurrentlyboth fore and aft of the piston axis at all times.

11. In a rotary, radial piston pump or motor, a rotatable barrel havinga radial cylinder, valve means for the cylinder, a radial flange on thebarrel in the zone of the cylinder, a radial guide- Way inthe flangehaving guide surfaces parallel to the cylinder axis, a pistonreciprocable in the cylinder, a radial head on the piston reciprocableradially in the flange guideway and guided thereby, and means carried bythe head and extending transversely therefrom and defining inner andouter tangential reactance surfaces at both faces of the head, saidsurfaces extending forwardly and rearwardly from the piston axis, androtary reactance means eccentric to the barrel and extending alongsidethe flange and radial head, and having. complementary` tangential waysoperatively engaging said inner and outer reactance engaging surfacesrespectively i for reciprocating the piston and for transmitting torquethrough the medium of the radial head portion between the barrel flangeand reactance means, and accommodating the said means for relativeoscillation thereof forwardly and rearwardly along the path of rotation.

12. In a rotary, radial piston pumpor motor, a rotatable barrel having aradial cylinder, valve means for the cylinder, a radial flange on thebarrel in the zone of the cylinder, a radial guideway in the flangehaving guide surfaces parallel to the cylinder axis, a pistonreciprocable in the cylinder, a radial head member on the piston andaccommodated between said surfaces and bridglng the space therebetweenand being reciprocable radially in the flange guideway and guidedthereby, a rotary reactance member eccentric to the barrel and extendingalongside the flange and radial head member, thrust means carried by oneof said members in the radial zone of the flangeand extendingtransversely of the head member and defining parallel inner and outertangential reactance surfaces extending forwardly and rearwardlyfromfthe piston axis, one of said members having complementary waysparallel to and operatively associated with said inner wardly along thepath of rotation, means securing the thrust means to one of said membersin xed position tangentially thereof with said reactance surfacesconstrained against bodily rotation relative to both members, saidthrust means being in rolling engagement with the tangential surfacesboth fore and aft of the piston and adjacent the piston at all times.

13. In a rotary, radial piston pump or motor, a rotatable barrel havinga radial cylinder, valve means for the cylinder, a radial flange on thebarrel in the zone of the cylinder, a radial 'guideway in the fiangehaving guide surfaces parallel to the cylinder axis, and positioned inadvance of and to the rear of the cylinder respectively, a pistonreciprocable in the cylinder, a` radial head on the piston reciprocableradially in and guided by the flange guideway, andhaving a tangentiallyextending operating Way therethrough, a rigid thrust plate accommodatedin the tangential operatingway and having its ends engaged with thereactance in non-rotative relation with respect to the reactance andhaving a tangential portion in the tangential operating wayforcooperation therewith both fore and aft of the piston axis concurrentlyat all times.

- 14. In a rotary radial piston pump. or motor, a-

rotatable barrel havingl a rigid cylindrical portion and radialcylinders therein, valve means for the cylinders, a radialvtorque flangeon the rigid cylindrical portion in the zone of the cylinders andextending radially outwardly from the cylindrical portion, guideways inthe flange and aligned with the cylinders respectively, each guidewayhaving guide surfaces parallel to each other and to the axis of theassociated cylinder, pistons reciprocable in the cylinders respectively,rigid heads for the pistons respectively and reciprocable in theassociated guideways, thrust means carried by and extending laterallyfrom each head and defining rigid tangentially elongated operatingsurfaces at each side of the associated head, which-surfaces areconstrained from bodily rotation with respect to the associated head, arotary reactance eccentric to the barrel reactance plate elementsadjustably and turnand having tangential operating ways accommodatingthe thrust means with said rigid tangentially extending surfaces incooperation with the ways for oscillation therealong to effect load andtorquetransmission between the barrel and reactance.

15. In a rotary radial piston pump or motor, a rotatable barrel having arigid cylindrical portion and radial cylinders therein, valve means forthe cylinders, a radial torque flange on the rigid cylindrical portionin the zone of the cylinders and extending radially outwardly from thecylindrical portion, guideways in the flange and aligned with thecylinders respectively, each guideway having guide surfaes parallel toeach other and to the axis of, the associated cylinder, pistonsreciprocable in the cylinders respectively, a rigid head member for eachpiston reciprocable in the associated guideway, a rotary reactancemember eccentric to the barrel and having portions alongside the headmember, one of said last named members having tangential ways, rigidthrust means extending transversely of the members and connected to theother one of said members and defining tangential surfaces which arenon-rotative bodily with respect to the member by Whichthe thrust meansVis carried and which are accommodated in said tangential ways of theother member.

16. In a pump or motor of the variable displacement radial piston type,aV casing, a valve pintle supported therein, a piston cylinder barrelIin telesc'oping relation to the pintle, radial ways in the barrelaligned with the pistons, crosshead elements for the pistons in saidways, transverse openings in the crosshead elements anda plurality ofcrosspins carried in said openings in balanced arrangement relative tothe piston axes,

ably mounted in the casing and having openings to receive the pins, ltheopenings in one o! said elements comprising slots for allowing freetravel of the crosspins relative to said slotted element while guidingthe pins for definite travel, and antii'rictional needle bearings in theopenings oi the coacting element for securing the pins for free rotationonly in said coacting element. l

17. Mechanism according toclaim 16, wherein each of the crossheadelements has a plurality of transverse bores supporting the needlebearings and pins and the face plates are slotted to receive the ends ofthe pins.

18. In a pump or motor of the radial piston type, a casing, a valvepintle mounted in the casing, a cylinder barrel in telescoping relationto I the pintle, a circular radial driving iiange carried by the barreland having circumferentially spaced openings therein, radial cylindersand crosshead ways aligned therewith in the plane of the flange,crosshead elements lexiblygco'nnected with the pistons and slidable insaid ways, face plate elements journalled in the casf ing on oppositesides of said ange and arranged to be adjusted transversely of the axisof the barrel for governing the stroke ofthe pistons, means passingthrough the ange and rigidly securing the face plate elements togetherin xed relationship to each other close to the ange, a plurality ofcrosspins in each ot saidcrosshead elements in balanced relation withrespect to the piston axes, the face plate elements having openingsreceiving the ends of the pins to.actu ate the pistons, and individualantifriction journal mountings for each ofthe pins in one of Itheaforesaid elements.

- ELEK K. BENEDEK.

